Type I Sialidosis in a Chinese family: a case report and literature review.

Background: Sialidosis is an autosomal recessive hereditary disease characterized by the mutation of neuraminidase-1 (NEU1) gene, resulting in decreased activity of α-N-acetylneuraminidase. This leads to metabolic abnormalities in various organs. Sialidosis is classified into two distinct clinical phenotypes, type I and type II, based on the age of onset and severity of clinical manifestations.

Case presentation: Here, we report a case involving a patient and his two sisters, all of whom showed seizures and ataxia during adolescence, with progressively worsening symptoms. Prior to admission, none of the patients had received a systemic diagnosis or treatment. The whole exome sequencing identified a homozygous NEU1 mutation (NM_000434.3:c.544A > G [p.Ser182Gly]) in all three siblings. Their parents and children, who were asymptomatic, were found to be heterozygous carriers. The three patients were ultimately diagnosed with type I sialidosis and treated with antiseizure medications, but they continued to experience recurrent seizures.

Conclusions: This case report enhances our understanding of sialidosis, particularly in patients presenting with seizures and ataxia. Furthermore, the gene sequencing is a crucial tool for confirming the diagnosis of sialidosis and provides a valuable approach for genetic counseling in affected families.